Claimed to be stronger than steel, this offers additional resistance
to penetration from road debris while being ultralight. Combined
with Continental's Black Chili rubber compound, super-tiny carbon
black particles incorporated into the rubber formula, the GP4000 S
II is versatile enough for race wheels or training wheels.

The
tiny size of Black Chili particles allows them to mold to variable
road surfaces more readily. It gives the tire greater ability to
conform to imperfections in the road surface for excellent grip in
demanding situations such as high speed cornering. Since the Black
Chili particles are so small, more particles fit into the contact
patch of the tire, reducing tire wear and increasing tire longevity.

The
Black Chili particles are also literally more flexible, which
reduces the rolling resistance of the GP 4000 S II. The Continental
GP 4000 S II is available in 700x23 and one color; Black/black.